This invention relates to the general field of construction of objects intended to remain exposed to the elements such as playground equipment, rustic structures, and the like. The structures are typically assemblies of wooden posts or poles, hereinafter called "timbers", and metal bar members, usually tubular, hereinafter called "tubes", and a very common problem is to interconnect such members inexpensively, conveniently, and in a manner which is not likely to cause damage to the timbers, such as causing them to split. Playground equipment particularly is subject to severe use, and must be extremely rigid and durable. No satisfactory way has been found for interconnecting the timbers and tubes by attachment to the pole surfaces, and it has become customary to cross bore the timbers so that they may be traversed by the tubes, which are thereafter secured to them. Arrangements of this sort are taught in Munger, et al, U.S. Pat. No. 3,814,416, and in the copending patent application of John M. Beattie, Ser. No. 433,612, filed Jan. 8, 1974, now U.S. Pat. No. 3,893,776, issued July 8, 1975 and assigned to the assignee of the present application.
As taught in the co-pending application, there is much advantage to be gained in the use of interconnecting fittings which provide a beneficial compression of the timbers in the area of the connection. It is also important, however, that fittings be producible at low cost, and usable in the field easily and efficiently.